The GPIO buffer load capacity is not specified in units of current. It is specified in terms of buffer drive strength or output impedance. For example, refer to the Section "GPIO Output Buffer Impedance" of the i.MX 6ULL Data Sheet(s).

I am just using Ohms law to determine the current for the GPIO when its 3.3V IO logic, Drive current form 20mA to 140mA as per "4.8.1 Single Voltage GPIO Output Buffer Impedance" in the datasheet. Am i right?

And we are going to use GPIO in sourcing power to the LED for Indication use case.